Total reflection fluorescence X-ray analyzers and surface particle detectors are commonly known as analyzers which conduct the evaluation of minute amounts of impurities or particles on a sample surface, for example a wafer surface.
The former is an analyzer which employs X rays and evaluates the minute amounts of heavy metal impurity contamination on a sample surface, while the latter is an evaluator for detecting fine particles deposited on a sample surface using, for example, a laser beam.
Using FIG. 16 below, a conventional total reflection fluorescence X-ray analyzer will be explained. In FIG. 16, reference 801 indicates an X ray source, and the X ray 802 generated therein is applied to sample 803 at an angle of incidence .theta. which fulfills total reflection conditions (for example, .theta.=0.05 degrees). As a result of the application of this X ray 802, fluorescence X rays 805 are emitted from impurity substances 804 deposited on the surface of sample 803. These are detected by X ray detector 806. These fluorescence X rays 805 have a wavelength (energy) specific to the contaminant substances 804, so that it is possible to determine the contaminant substances, and furthermore, it is possible to evaluate the degree of contamination from the strength of the fluorescence X rays 805.
Next, using FIG. 17, a conventional surface particle detector will be explained. In FIG. 17, Ref. 901 indicates a laser beam source, and the laser beam 902 generated therein scans the surface of a sample 904 by means of a light scanner 903 comprising, for example, a rotating polygonal mirror. If fine particles 905 have been deposited on the surface of sample 904, then the laser beam 902 will be irregularly reflected by fine particles 905, and the irregularly reflected light 906 will be detected by light detector 907, and the detection and evaluation of fine particles 905 thus conducted.
However, in the conventional apparatuses described above, the following problems are present. In the total reflection fluorescence X ray analyzer, the detection of heavy metals such as copper (Cu), iron (Fe), chromium (Cr), and the like, is possible; however, it is impossible to detect sodium (Na) or carbon (C), which constitute extremely important impurities in semiconductor processes. That is to say, there are limitations in the elements which are detectable. Furthermore, X rays are employed, so that some damage is caused to the samples. More concretely, in a Si substrate, or at the Si--SiO.sub.2 boundary, the bonds between atoms are broken, so that it is impossible to employ such an apparatus in the analysis of wafers during the manufacturing of devices. Furthermore, because X rays are employed, some danger is posed to the human body, and the X ray optical system and the detector are structurally complex. Furthermore, it is necessary to constantly conduct the liquid nitrogen cooling of the fluorescence X ray detector, so that the operation thereof is quite complex and difficult. On the other hand, in a surface particle detector, because the detection of light which is irregularly reflected by means of particles is carried out, testing using samples having irregularities other than deposited particles, such as pattern carrying wafers or the like, is impossible. Furthermore, there are problems in that the determination of the components of the deposited particles is impossible, and the like.
The present invention has as an object thereof to provide an analyzer capable of detecting light elements such as Na or the like, capable of evaluating samples having uneven surfaces, such as pattern carrying wafers or the like, without destroying or causing damage to the sample, having a simple composition and simple operation, and which is safe to the human body, and which is capable of identifying the composition of minute amounts of impurities or fine particles deposited on the surface of a sample.